Jorubai Murk Lurker gets +1/+1 as long as you control a Swamp.

: Target creature gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Devoid (This card has no color.)

When Murk Strider enters the battlefield, you may put a card an opponent owns from exile into that player's graveyard. If you do, return target creature to its owner's hand.

Delve (Each card you exile from your graveyard while casting this spell pays for .)

Flying

Murktide Regent enters the battlefield with a +1/+1 counter on it for each instant and sorcery card exiled with it.

Whenever an instant or sorcery card leaves your graveyard, put a +1/+1 counter on Murktide Regent.